1. Field of the Invention
The present invention relates to a roll with a function of arbitrarily adjusting the width of a horizontal roll of a universal mill that is applicable to rolling H-steels or the like.
2. Statement of the Prior Art
A width-variable horizontal roll has already been disclosed in which the width of the roll can be adjusted in accordance with individual sizes of various types of H-steels to be rolled. Disclosed initially was a method of providing a shim between sleeve rolls that are divided into two, or a method of forming external and internal threads in the two sleeve rolls. However, with either of these two methods, a width adjusting operation had to be carried out off the rolling line, and a tremendous amount of time and labor was required to carry out such an operation.
As a method to solve the above drawback, the official gazette of Japanese Patent Publication No. 28642/1989 discloses a horizontal roll in which a hydraulic cylinder is interposed between a pair of left and right sleeve rolls for moving one of the sleeve rolls in the axial direction, and in which an injection channel is also provided for forming an oil film on the outer circumference of the movable sleeve roll and an arbor over which the movable sleeve roll is fitted in order to facilitate the movement of the movable sleeve roll by the hydraulic cylinder.
Although the latter method in which external and internal threads are formed in the two sleeve rolls enables the adjustment of the roll width by remote control of the horizontal roll while it is permitted to remain on the rolling line, since a hydraulic cylinder is used as a means for moving one of the rolls in the axial direction, it has a drawback that a complicated hydraulic pressure control device is required. On top of this, precise fine adjustment of hydraulic pressure is very difficult.